A. Field of the Invention
The field of the present invention relates generally to landscape edging used for creating borders or dividers around various landscape features, such as gardens, lawns, flower beds, trees and the like, so as to form a boundary between adjacent landscaped areas. More particularly, the present invention relates to landscape edging strips that are flexible to use and inexpensive to manufacture. Even more particularly, the present invention relates to such landscape edging strip that is produced by co-extruding different materials and which is can be cut at any point along the strip.
B. Background
Landscape edging strips are utilized for borders or dividers so as to separate one portion of a landscaped area from other portions of the landscaped area or from non-landscaped areas and to provide a minimal barrier to the movement of water between adjacent areas. Because most landscaping does not follow nice straight lines, landscape edging strips are generally made out of materials and configured such that the individual strips are somewhat flexible. In addition, because landscape edging strips must be provided in section lengths that are suitable for sale, transport and handling, as opposed to being provided in single fixed-length sections, it is necessary that a mechanism be provided to interconnect the individual landscaping strips into lengths sufficient to extend the full distance around the desired landscape area. Due to the outdoor environmental use for landscaping edging strips, it is well known that landscape edging strips must be made out of materials that are suitably resistant to corrosion, mildew and pests. Generally, landscape edging strips are configured to be anchored into the ground either directly by hammering or otherwise hitting or pushing the edging strips themselves into the ground or by way of separate stakes that are configured to be placed in the ground so as to hold the strips in their desired position. Because the landscape edging is used in and around areas where gardening tools and activity takes place, it is necessary that the landscape edging be sufficiently durable to maintain its functionality when contact, inadvertent or otherwise, with such tools and activity occurs. In addition, because landscaped areas are generally designed to be visually appealing, it is important that the landscape edging be made out of materials and be configured such that, at the least, it does not significantly detract from the visual nature of the landscaping.
Many different materials are utilized for landscape edging strips to achieve various functional and aesthetic objectives. For instance, edging strips have been made out of relatively thin strips of metal, including aluminum and steel, for some time. Often these metal edging strips are painted green or other colors to attempt to blend in with the landscaped areas and are coated or otherwise treated to reduce the likelihood of corrosion. To solve the inevitable corrosion problem, many manufacturers make the edging strips out of plastic and like materials, which are typically selected for specific cost, appearance, durability, flexibility and weight characteristics. In addition, plastic materials are selected based on their ability to resist cracking, discoloration, ultraviolet light intrusion and mildew. Plastic edging strips can be made in a variety of different shapes by a variety of different process. Some materials are known to have certain characteristics that achieve certain desired objectives but do not do well at others. For instance, a material may be very durable, but be lacking in the flexibility, appearance and/or cost characteristics or result in an edging strip that weighs too much to be practical. As a result, the desired material that provides as much positive attributes as possible often results in a relatively expensive edging strip.
A significant number of prior art landscape edging systems, utilizing a wide range of materials and configured in a variety of different ways, are known in the industry. Some of these prior art edging materials, exemplified by U.S. Patent Publication No. 2003/0024157 to Conde (published Feb. 6, 2003), U.S. Pat. No. 5,720,128 to Smith, et al., U.S. Pat. No. 5,456,045 to Bradley et al. and U.S. Pat. No. Des. 426,322 to Anderson, et al. are configured such that at least a portion of the edging is shaped to permit it to be inserted into the ground to form the edging boundary. For instance, the patents to Bradley, et al. and Anderson and the patent publication to Conde, utilize variable contoured bottom edges that have a series of arches and points and which are tapered to facilitate insertion into the ground. The patent to Smith, et al. describes landscape edging having an elongated vertical plate with a lower longitudinal edge adapted for piercing engagement with the ground. Other patents, such as U.S. Pat. No. 5,375,369 to VerHoeve, U.S. Pat. No. 5,117,583 to Reum, U.S. Pat. No. 4,823,521 to Kontz, Jr. and U.S. Pat. No. 2,782,561 to R. A. Smith, utilize stake portions that is attached to (i.e., part of) the edging strip or attachable to the edging strip and which are configured to be driven into the ground. U.S. Pat. No. 5,301,461 to Zwier discloses a landscape edging that has an elongated ribbon strip configured to receive a ground-engaging stake and U.S. Pat. No. 5,157,867 to Fritch discloses a landscape edging that has a generally horizontal flat mowing strip through which one or more spikes or stakes are driven into the ground. Other landscape edging systems, such as U.S. Pat. No. 3,788,001 to Balfanz, Jr. and U.S. Pat. No. 2,821,809 to Collier, have a portion of the edging strips buried or covered by soil or other landscaping materials.
The different prior art landscape edging systems disclose a variety of connectors used to connect one strip to another. For instance, the patents to Fritch, Reum and Kontz, Jr. identified above disclose the use of separate insertable connectors that fit within tubular sections of adjacent edging strips. The patents to Smith, et al., Bradley, et al., Zwier, Collier, R. A. Smith and Anderson, et al. disclose the use of the attached connectors that interlock, in one form or another, with an adjacent edging strip to form a somewhat continuous strip of landscape edging. The patent to Balfanz, Jr., discloses the use of a generally C-shaped connector with flanges that interconnects the upper portion of T-shaped edging strips.
The various prior art landscape edging systems, including those identified above, have various advantages and disadvantages that affect the cost, functionality and usefulness of the edging strips. For instance, while the art of plastic extrusion in general is well known (for instance for fencing as disclosed in U.S. Pat. No. 3,933,311 to Lemelson and for co-extruded synthetic wood components U.S. Pat. No. 6,579,605 to Zehner and roofing shingles in U.S. Pat. No. 6,546,688 to Parsons), none of the above edging systems disclose or suggest the use of edging strips that are made out of a double-layer plastic extruded material that provides significant cost, weight and appearance benefits with the use of multiple channels for receiving a connector anywhere along the edging strips where it is desired to cut the strip. The patent to Zehner discloses a wood component having an interior layer made out of a first synthetic wood composition layer co-extruded with a outer second synthetic wood composition layer to reduce cost by utilizing an inexpensive and lower weight interior layer integrally formed with the better quality outer layer. Compared to a single layer material, an edging strip made out of multiple layered materials provides the desired characteristics for the edging strip at a significantly reduced overall cost and, if desired, weight. The manufacturing or prior art edging strips generally requires the manufacturer to execute a secondary operation to make the edging strip's connection mechanism, such as drilling holes or making a lap joint. These secondary operations make the edging strip more difficult and more expensive to manufacture. They can also make the edging system (i.e., the edging strip and connection mechanism) more difficult to use. Therefore, what is needed is landscape edging strip that utilizes lower weight and cost materials and which does not require any secondary operations to manufacture or prepare the edging strip for the connector. The preferred edging strip should be relatively inexpensive to make, easy to use and adaptable for use as landscape edging. To be effective, such landscape edging should allow the user to cut the strip at any place desired and still be able to utilize connectors to join two adjacent strips together. In addition, the preferred edging strip should provide an aesthetically appealing boundary.